I thought I screwed myself by maxing out point defence (lots x small hits), the later enemies have too much defence, so I made a couple big single shot ships which starting to get all the kills.
However the commander vesel is awesome, I concentrated on it giving other ships lots of attack buff, this made the multi hit attacks mostly one shot kils even against the hardest enemies, then that same command vesel put up loads of defence buff and bingo, 2 ships can beat almost any level!
Point Defence, Corrosive Torp, Issue Orders, Formations = WIN (3 ships)
 "Engage"){kind=icon}
 "Cargo Bridge"){kind=icon}